Conventionally, it is known that genetic analysis is possible by labeling a DNA as a target biomolecule with a fluorescent substance, directing laser light thereto to excite the fluorescent substance, and reading the generated fluorescence. The fluorescence of the fluorescent substance used for the labeling is very weak. Therefore, a material of a fluorescence detection and analysis substrate used for the genetic analysis as described above is often glass or silicon having low autofluorescence.
A material of a fluorescence detection and analysis substrate is required to be transparent, highly processable, highly chemical-resistant, highly heat-resistant, producible at low cost and the like in addition to being low in autofluorescence as described above. In the case where glass is used as a material of a fluorescence detection and analysis substrate, there are problems that, for example, the processability is not absolutely high and the production cost is high. In the case where silicon is used as a material of a fluorescence detection and analysis substrate, the processability is high because etching and photolithography are usable but there is a problem that the transparency is low.
In general, a plastic material used for a substrate (support) for fluorescence detection and analysis is preferably transparent from the point of view of detection sensitivity. Plastic materials that are being studied as a material of the substrate include, for example, an aromatic polycarbonate resin, a polystyrene resin, a saturated cyclic olefin-based resin, an acrylic resin and the like. With the above-described fluorescence detection and analysis method, in the case where the fluorescence (autofluorescence) derived from the substrate is high, the background of the substrate is high at the time of detection, and thus the S/N ratio is lowered to decrease the detection precision. Therefore, it is important that the material of a fluorescence detection and analysis substrate should be low in autofluorescence.
An aromatic polycarbonate resin has superb properties of transparency, heat resistance, transferability and the like, and thus is used in various fields for compact discs, light guide plates of liquid crystal devices, light diffusers and the like. Therefore, it has been attempted to use an aromatic polycarbonate resin for a fluorescence detection and analysis substrate (see, for example, Patent Document 1).
In the meantime, an aromatic polycarbonate resin has an aromatic ring, and therefore, has a characteristic of having higher potential autofluorescence than other transparent resins. Namely, although a material for a fluorescence detection and analysis substrate is generally required to have low autofluorescence (low background) in a visible light wavelength range (400 nm to 750 nm), the aromatic polycarbonate resin has autofluorescence in this visible light wavelength range and thus has high background. For this reason, the aromatic polycarbonate resin has a problem of not being suitable for a fluorescence detection and analysis substrate.
In such a situation, use of resins other than the aromatic polycarbonate resin, which is difficult to use for a fluorescence detection and analysis substrate, has been studied. Specifically, for example, as a fluorescence detection and analysis substrate that is transparent and has relatively low autofluorescence, a substrate formed of a saturated cyclic olefin-based resin has been proposed (see, for example, Patent Document 2).
A fluorescence detection and analysis substrate formed of a polyester containing alicyclic dicarboxylic acid and alicyclic diol as main components has also been proposed (see, for example, Patent Document 3). Patent Document 4 will be described later.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2002-14100
Patent Document 2: Japanese Laid-Open Patent Publication No. 2001-231556
Patent Document 3: Japanese Laid-Open Patent Publication No. 2005-179410
Patent Document 4: Japanese Patent No. 4903518